Speaking to Beth Simmons of Tuscon's 96.1 KLPX (embedded below), Campbell said, "I've heard a rumor. I don't know if it's for public consumption yet. But it would be pretty easy to figure it out. It's a gentleman who's been a big fan of the band and a friend of the band for many, many decades."

He then described the mystery man as being "really smart." That caused Simmons took to bring up the name of May, an astrophysicist who has worked with NASA on their New Horizons project.

"It may well be," Campbell responded.

For Campbell, the induction is a validation for his band after years of being overlooked by the critics. "In Leppard, we've never been the sort of band that's gotten many industry accolades, although we've got a tremendously faithful fanbase and we always have, for many, many years," he continued. "And I think one of the most exciting aspects about getting into the Hall of Fame is we actually got the biggest-ever fan vote. So I think that kind of means as much, if not more, to us."

This summer, Def Leppard will begin their second residency in Las Vegas, playing 12 dates at the Zappos Theater at Planet Hollywood Resort & Casino between Aug. 14 and Sept. 7. In 2013, they played nine shows where they performed 1987's Hysteria in its entirety.